Design of Runoff Recycling Irrigation System for Rice Cultivation

Abstract

Design of a runoff-recycling-based irrigation system to provide irrigation for rice in monsoon season is a complex problem. The irrigation requirement, as well as the water availability in the form of runoff, vary both in amount and time. The design of an irrigation system based on the irrigation requirement obtained from short-period experiments may lead to faulty design. To overcome this, a simulation study of water balance of the cropped area as well as the tank has been done to determine the catchment command area ratio and size of the tank for a five year return period. It has been found that for transplanting within optimum period, the catchment command ratio should be 5.0 or more and a tank of storage capacity of 132.6 mm will be sufficient at a return period of five years for the U.P. midhills of India. It has also been found that a short-duration variety will be more suitable for such an irrigation system.